Use of ERS-1 SAR data for forest monitoring in South Sumatra

In the frame of the joint ESA-CEC TREES project, the capacity of ERS-1 SAR data for mapping tropical forest, has been evaluated. The authors investigate new methods of discriminating forests from deforested areas using ERS-1 data over South Sumatra. The method developed is based on the temporal variation of the radar backscatter assessed by the ratio between two images, which permit to reduce the effect of terrain topography. The results show that using multitemporal data, with optimal acquisition periods, good forest/non forest discrimination could be achieved with the ratio based classifier. The investigation of 5 multitemporal ERS-1 images permitted to build a forest/non forest map of the South of Sumatra (60 000 km²)